feat(store): add working hash (#15712)

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
Co-authored-by: Marko <marbar3778@yahoo.com>

store/CHANGELOG.md

@@ -27,6 +27,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+- [#15712](https://github.com/cosmos/cosmos-sdk/pull/15712) Add `WorkingHash` function to the store interface  to get the current app hash before commit.
 * [#14645](https://github.com/cosmos/cosmos-sdk/pull/14645) Add limit to the length of key and value.
 * [#15683](https://github.com/cosmos/cosmos-sdk/pull/15683) `rootmulti.Store.CacheMultiStoreWithVersion` now can handle loading archival states that don't persist any of the module stores the current state has.
 

store/iavl/store.go

@@ -143,6 +143,16 @@ func (st *Store) Commit() types.CommitID {
 	}
 }
 
+// WorkingHash returns the hash of the current working tree.
+func (st *Store) WorkingHash() []byte {
+	hash, err := st.tree.WorkingHash()
+	if err != nil {
+		panic(fmt.Errorf("failed to retrieve working hash: %w", err))
+	}
+
+	return hash
+}
+
 // LastCommitID implements Committer.
 func (st *Store) LastCommitID() types.CommitID {
 	hash, err := st.tree.Hash()

store/iavl/tree.go

@@ -27,6 +27,7 @@ type (
 		DeleteVersions(versions ...int64) error
 		Version() int64
 		Hash() ([]byte, error)
+		WorkingHash() ([]byte, error)
 		VersionExists(version int64) bool
 		GetVersioned(key []byte, version int64) ([]byte, error)
 		GetImmutable(version int64) (*iavl.ImmutableTree, error)
@@ -101,3 +102,7 @@ func (it *immutableTree) LoadVersionForOverwriting(targetVersion int64) (int64,
 func (it *immutableTree) LazyLoadVersionForOverwriting(targetVersion int64) (int64, error) {
 	panic("cannot call 'LazyLoadVersionForOverwriting' on an immutable IAVL tree")
 }
+
+func (it *immutableTree) WorkingHash() ([]byte, error) {
+	panic("cannot call 'WorkingHash' on an immutable IAVL tree")
+}

store/mem/store.go

@@ -58,3 +58,5 @@ func (s *Store) GetPruning() pruningtypes.PruningOptions {
 }
 
 func (s Store) LastCommitID() (id types.CommitID) { return }
+
+func (s Store) WorkingHash() (hash []byte) { return }

store/rootmulti/dbadapter.go

@@ -9,6 +9,11 @@ import (
 
 var commithash = []byte("FAKE_HASH")
 
+var (
+	_ types.KVStore   = (*commitDBStoreAdapter)(nil)
+	_ types.Committer = (*commitDBStoreAdapter)(nil)
+)
+
 //----------------------------------------
 // commitDBStoreWrapper should only be used for simulation/debugging,
 // as it doesn't compute any commit hash, and it cannot load older state.
@@ -32,6 +37,10 @@ func (cdsa commitDBStoreAdapter) LastCommitID() types.CommitID {
 	}
 }
 
+func (cdsa commitDBStoreAdapter) WorkingHash() []byte {
+	return commithash
+}
+
 func (cdsa commitDBStoreAdapter) SetPruning(_ pruningtypes.PruningOptions) {}
 
 // GetPruning is a no-op as pruning options cannot be directly set on this store.

store/rootmulti/store.go

@@ -497,6 +497,37 @@ func (rs *Store) Commit() types.CommitID {
 	}
 }
 
+// WorkingHash returns the current hash of the store.
+// it will be used to get the current app hash before commit.
+func (rs *Store) WorkingHash() []byte {
+	storeInfos := make([]types.StoreInfo, 0, len(rs.stores))
+	storeKeys := keysFromStoreKeyMap(rs.stores)
+
+	for _, key := range storeKeys {
+		store := rs.stores[key]
+
+		if store.GetStoreType() != types.StoreTypeIAVL {
+			continue
+		}
+
+		if !rs.removalMap[key] {
+			si := types.StoreInfo{
+				Name: key.Name(),
+				CommitId: types.CommitID{
+					Hash: store.WorkingHash(),
+				},
+			}
+			storeInfos = append(storeInfos, si)
+		}
+	}
+
+	sort.SliceStable(storeInfos, func(i, j int) bool {
+		return storeInfos[i].Name < storeInfos[j].Name
+	})
+
+	return types.CommitInfo{StoreInfos: storeInfos}.Hash()
+}
+
 // CacheWrap implements CacheWrapper/Store/CommitStore.
 func (rs *Store) CacheWrap() types.CacheWrap {
 	return rs.CacheMultiStore().(types.CacheWrap)

store/rootmulti/store_test.go

@@ -128,12 +128,16 @@ func TestHashStableWithEmptyCommit(t *testing.T) {
 	store1 := ms.GetStoreByName("store1").(types.KVStore)
 	store1.Set(k, v)
 
+	workingHash := ms.WorkingHash()
 	cID := ms.Commit()
 	require.Equal(t, int64(1), cID.Version)
 	hash := cID.Hash
+	require.Equal(t, workingHash, hash)
 
 	// make an empty commit, it should update version, but not affect hash
+	workingHash = ms.WorkingHash()
 	cID = ms.Commit()
+	require.Equal(t, workingHash, cID.Hash)
 	require.Equal(t, int64(2), cID.Version)
 	require.Equal(t, hash, cID.Hash)
 }
@@ -159,7 +163,9 @@ func TestMultistoreCommitLoad(t *testing.T) {
 	// Make a few commits and check them.
 	nCommits := int64(3)
 	for i := int64(0); i < nCommits; i++ {
+		workingHash := store.WorkingHash()
 		commitID = store.Commit()
+		require.Equal(t, workingHash, commitID.Hash)
 		expectedCommitID := getExpectedCommitID(store, i+1)
 		checkStore(t, store, expectedCommitID, commitID)
 	}
@@ -172,7 +178,9 @@ func TestMultistoreCommitLoad(t *testing.T) {
 	checkStore(t, store, commitID, commitID)
 
 	// Commit and check version.
+	workingHash := store.WorkingHash()
 	commitID = store.Commit()
+	require.Equal(t, workingHash, commitID.Hash)
 	expectedCommitID := getExpectedCommitID(store, nCommits+1)
 	checkStore(t, store, expectedCommitID, commitID)
 
@@ -211,7 +219,9 @@ func TestMultistoreLoadWithUpgrade(t *testing.T) {
 	require.Nil(t, s4)
 
 	// do one commit
+	workingHash := store.WorkingHash()
 	commitID := store.Commit()
+	require.Equal(t, workingHash, commitID.Hash)
 	expectedCommitID := getExpectedCommitID(store, 1)
 	checkStore(t, store, expectedCommitID, commitID)
 

store/transient/store.go

@@ -39,8 +39,12 @@ func (ts *Store) GetPruning() pruningtypes.PruningOptions {
 }
 
 // Implements CommitStore
-func (ts *Store) LastCommitID() (id types.CommitID) {
-	return
+func (ts *Store) LastCommitID() types.CommitID {
+	return types.CommitID{}
+}
+
+func (ts *Store) WorkingHash() []byte {
+	return []byte{}
 }
 
 // Implements Store.

store/types/store.go

@@ -22,6 +22,9 @@ type Committer interface {
 	Commit() CommitID
 	LastCommitID() CommitID
 
+	// WorkingHash returns the hash of the KVStore's state before commit.
+	WorkingHash() []byte
+
 	SetPruning(pruningtypes.PruningOptions)
 	GetPruning() pruningtypes.PruningOptions
 }